Abstract This study was designed to compare the block characteristics of plain 0.5% ropivacaine (Group RR) versus the addition of 1 mcg/kg dexmedetomidine (Group RD) or 50 mcg/kg midazolam (Group RM) as adjuvants to ropivacaine in ultrasound guided supraclavicular BPB. Primary objective was to assess the duration of sensory and motor block. Time taken for onset of block, sedation scores were also noted.

METHODS : After obtaining Institutional Ethics committee clearance, 60 patients posted for elective upper limb surgeries under supraclavicular BPB were randomly allocated to one of the 3 groups. A written informed consent obtained. Block was performed using 31 ml of study medication. The block characteristics were assessed every 3 minutes from the time of injection till onset of complete blockade, then hourly for 24 hours. Apart from sensory block (pin prick) and motor block (Modified Bromage scale), sedation was also assessed.

RESULTS : The duration of blockade (minutes) was significantly longer in Group RD (907+/- 205) compared to Group RR (597+/-101) and Group RM (605+/-188). There was no difference among the groups with respect to onset of sensory and motor blockade. The sedation scores were significantly higher in Group RD (Median=3) and Group RM (Median=2).

CONCLUSIONS : Addition of dexmedetomidine to local anaesthetic in USG guided supraclavicular brachial plexus block prolongs blockade and analgesia. Both additives when added also produced sedation with higher score in Group RD.